NEW YORK, Aug 21 (Reuters) - High pump prices strained U.S. gasoline demand over the last two weeks as motorists chose to stay put rather than pay more for the fuel, MasterCard said in its biweekly SpendingPulse report on Tuesday.
Gasoline demand fell 2.3 percent from a year ago in the two weeks ending Friday while the price of a gallon rose 18 cents, according to MasterCard's report.
Demand dropped 1.9 percent between the week ending on Aug. 10 and the one ending on Aug. 17, the report added. Last week's four-week moving average for demand was 2.7 percent lower than a year earlier.
At an average $3.71 a gallon, prices were 3.3 percent higher than a year earlier.
MasterCard Advisors, a unit of MasterCard Inc, estimates retail gasoline demand based on aggregate sales in the MasterCard payments system, coupled with estimates for other payment forms, including cash and checks.
It changed the frequency of its report this summer from weekly to every other week.